1. Field of the Invention
The present invention relates to a wheel suspension for a motor vehicle, having a transverse control arm that can be attached to a vehicle body by way of bearings and can be rotated about a longitudinal axis, and having a body spring configured as a torsion bar spring, for absorbing rotational movements of the transverse control arm about the longitudinal axis. The body spring is disposed on the transverse control arm so as to rotate with it, with a first end. An electromechanical actuator for changing the angle of rotation of the body spring is disposed at a second end of the body spring. The wheel suspension is particularly provided as a single-wheel suspension, on at least one axle of a passenger car or a utility vehicle.
2. The Prior Art
A wheel suspension for a motor vehicle, having the characteristics described initially, is known from the reference DE 39 28 062 A1, in which the body springs configured as torsion bar springs can be twisted by means of an electromechanical actuator. In this manner, side-to-side movements of the motor vehicle when driving through a curve can be compensated, on the one hand. On the other hand, in this way the wheel height level is adjustable independent of static or dynamic forces that act on the wheel suspension.
In the wheel suspension known from DE 38 31 338 A1, an additional torsion bar spring is provided in addition to the body spring, as a stress relief spring. Both the body spring and the stress relief spring are configured in tubular shape, and disposed coaxially. The stress relief spring surrounds the body spring and the torsion bar springs are rigidly connected at one end, by way of a coupling point. At the opposite end of the torsion bar springs, the body spring is connected with the vehicle body, and the stress relief spring is connected with the transverse control arm.
A device that can be hydraulically activated is disposed between the coupling point and the transverse control arm, for adjusting the angle of rotation. The transfer of force from the coupling point to the vehicle body takes place by way of the body spring disposed inside of the stress relief spring. By an active control of the hydraulic adjustment device, low-frequency vibrations can be compensated by a change in the bias of the torsion bar springs at the coupling point. The stress relief spring brings about the result that the adjustment device can be designed for relatively small setting moments.
The known system for active vibration compensation, in which a hydraulic adjustment device is connected with a hydraulic source by way of hydraulic lines and with the interposition of a controllable regulation and setting element, is technically complicated. Furthermore, the damping characteristics of the wheel suspension require further improvement, particularly in the high-frequency range. To guarantee a clearly defined damping behavior of low-frequency vibrations, the adjustment device must have sufficient rigidity. This rigidity is difficult to achieve with a hydraulic system.